New wireless keyboard / mouse combo

[steely dan]

My old Logitec keyboard / mouse combo gave up and I was convinced it was the bluetooth dongle. I purchased a new MK300 combo and went to set it up but have found that when my dell PC powers up and goes into user selection page I cannot get the new combo to connect/ operate  to/ with  the PC and therefore cannot select any user  to get into a mode that I configure the combo. I have checked the new combo on my Dell inspiron laptop and the keyboard and mouse operate OK. I have also tried a wired mouse and keyboard on the PC and again I cannot get any pointer movement at the user selection stage . I'm at a loss to think how I can get the mouse to operate and thus allow me to get into operational mode .
The Dell PC is running XP 2005
The old combo has been disposed of so I cannot use it to get running.
Thanks in advance .

[Allan]

Check bios for a setting that supports USB at boot. You may need to use a ps2 keyboard to get into the bios.

[steely dan]

Used a ps2 keyboard and managed to get into BIOS on start up .Unfortunatly when in BIOS and being offered options including safe Mode ,the arrow keys are not working and I therefore cannot scroll to any of these options and select!!!!!